POLITICS, we know, is a dirty business. The alliances and betrayals, triumphs and failures, the helping hands and hidden knives: no wonder thriller writers keep returning to the spoor.

The international thriller used to be set in a divided world of unstable stability. The format invariably involved a threat to the fragile balance. One side undermined the other; one element (almost always dissident or power-crazed) fought another, betrayed its own side or became intent on abusing power. In domestic politics, there was the same kind of uneasy balance: politicians who claimed to act on behalf of the poor and downtrodden, and those who represented the rich.

Thanks first to Mikhail Gorbachev, and now even more so to Bill Clinton and Tony Blair, the dividing lines are not so clear. East is no longer red, though it is the wild west. Politicians of the left, like Messrs Clinton and Blair, do not march with the people. They hobnob with the rich, take their holidays in the Seychelles (a synonym and haven for mercenaries and deposed heads of state) and talk mysteriously of a “third way”. In this unfamiliar world, it is no longer possible to typecast characters as wearing either white hats or black. In hats today, grey is the new black-or-white. It makes the political thriller writer's task more difficult, though surely more intriguing. Yet power has not stopped being power and it still attracts fortune-hunting moths which get too close to the heat. One such lepidopteran in Henry Horrock's “Potomac Fever”—a bar girl trying to hustle her way to a richer life—turns up dead on the shore of Chesapeake Bay. The bizarre marks on her body might mean a ritualised sex killing, but ensuing events—a shoot-out by a youth-gang, a sniper killing in a soon-to-be developed part of Washington, DC, and an attack on the investigating detective—make the murder part of something bigger.

This really is a crime thriller, but the smell of power seeping gradually on to the pages soon makes it plain that there is more political orchestration than you might think. The question is: from how far up the greasy pole does it come and what property or drug money is greasing whose palms? This is a nicely formed and pacy tale, but apart from telling us what we already suspect—that drug wealth is more corrosive to our society than communism ever was—it does not take us much further forward.

Stanley Johnson's unusual environmental thriller, “Icecap”, is set partly in Antarctica. “Great God, this is an awful place,” wrote Robert Falcon Scott, a British explorer, when he arrived at the South Pole in 1912. Historians, explorers and polar enthusiasts have long puzzled over the circumstances of Scott's death, which followed not long after. Many regard his insistence on retrieving a large quantity of geological samples during his descent of the Beardmore glacier as the height of folly given that his team was already suffering from malnutrition and bad weather. Did the delay, while he collected the samples, lead directly to the death of his team just a few miles from safety?

Mr Johnson turns the question on its head in “Icecap”. The novel's unlikely hero, a bumbling British journalist, sets off to prove that Scott did not die in vain after all. What if, he asks, the rocks he found hold the key to saving the planet? The device Mr Johnson uses to advance his hopeful thesis stretches credibility somewhat: Scott's rocks turn out to contain an unknown mineral, dubbed Falconite, in his honour, with near-magical properties.

The reason “Icecap” works is that Mr Johnson is particularly good at weaving his hopes for Scott's journey into a more arresting notion, that global warming could inspire the next cold war. He starts with the broadly accepted premise that greenhouse gases are a serious threat to the world, but argues that there will be winners too. A complex, larger-than-life Russian scientist is the anti-hero who masterminds his country's efforts to manipulate the global environment. The Russians want to get their hands on Falconite, despite international accords forbidding the commercial exploitation of Antarctica. That is because Russia, in particular, could reap enormous economic and geopolitical gains from global warming. Even a modest thaw would free its vast mineral resources now trapped under tundra and taiga, and open its ice-bound northern shipping lanes to Asia.

The future may be much more complex than we think, as Alan Furst's tale from the past indicates. Paris during the second world war is the setting for “Red Gold”. The surprising delicacy of the book lies in portraying how the human spirit refused to be crushed by the oppressive menace of Nazi occupation, not in the cliché mould of heroic resistance, but in the determination of, in this case, communist partisans, to wage a little private struggle with the Gaullist resistance against whom they might be pitted in the future.

The prose is as meagrely rationed as wartime food, the high political background only fleetingly hinted at, and the dangers emanating not just from the occupiers but the occupied as well are clearly but subtly expressed. In times of great upheaval, you can trust no one, says Mr Furst, especially when the moments of greatest risk appear to have passed, a point stressed to stunning effect in the very last sentences.

This too is the message from “Havana Bay”, Martin Cruz Smith's highly original setting for a welcome return by Arkady Renko, the sardonic and much-abused investigator hero of his “Gorky Park” trilogy, who has been privately summoned to Cuba to inquire into the death of a Russian official.

Few places can better exemplify the weird extremes of the post-Soviet world than Cuba, so pitifully deprived of its Soviet-block support that prostitution and scavenging for western crumbs are the people's principal occupations while Fidel Castro pretends socialism is still being built.

In reality, it is the nastier end of capitalism which is breaking through the bulwarks, and it is at the nexus of the conflict between the two great ideologies that Renko, at the point of succumbing to the collapse of his own life and as welcome in Cuba as a Miami croupier in Castro's villa, finds himself.

In such circumstances, as indeed in the previous Renko stories, there can be no justice as we commonly understand it. And yet Mr Smith manages to engineer a kind of justice, both for Renko and for Cuba, which is messy enough to bring the book to a satisfying conclusion.

What “Havana Bay” suggests is that the immediate past is far from being history and still haunts us. This is also the theme of “Remembrance Day”, a remarkably powerful first thriller by Henry Porter, a talented British journalist. He bases his tale in Northern Ireland around an awful but necessary dilemma: that settling civil conflicts such as those that have racked Ulster eventually requires the bitterest of enemies to shake hands and live peaceably with each other.

We praise such reconciliation, but those who have seen friends and colleagues die for a cause might consider it a betrayal. When a bomb causes carnage on a London bus, is it the work of fanatical Irish republicans, or someone else? Mr Porter weaves into the hunt for an extremely ingenious terrorist a sub-plot of a power struggle between the police anti-terrorist squad and MI5. Both agencies are intent on exorcising their own ghosts, and Mr Porter's portrayal of their ceaseless intriguing could not be bettered.

Demons created by official duplicity are one thing; far more disturbing are the spectres of the soul which are raised by Leon Uris. Unsurprisingly, given the long pedigree of his writing, “A God in Ruins” deals with anti-Semitism, which Mr Uris strongly fears is still a social sub-current waiting to erupt.

As the ethnic and religious pogroms that you might have thought had been banished make a comeback in Europe, not to mention the many Internet websites that testify to emboldened hatreds, it is a credible thesis which Mr Uris puts into the context of an American presidential campaign. The Democrat candidate, an adopted child who thought he was Roman Catholic, discovers eight days before polling day that in fact he is liable to be America's first Jewish president. So how would America react? Especially to a Jewish candidate whose political reputation had been earned by a crackdown on guns?

It might be argued that thriller fiction is not the best medium for raising or indeed answering questions like these. Nonetheless, these books are read by millions of people, rather more than would read professorial essays on morality in academic journals. And indeed, the best of these books sell because they touch something within us that wants or needs to be communicated.

The world they portray is a rather disturbing one, far removed from the secure and stable earth that most of us hoped would emerge as the cold war melted away. It seems to be an unsure place, where loyalties are insubstantial and unreliable, and it is haunted by ghosts of recent and ancient origin. A little worrying perhaps, but in the right hands always a great subject.